My service engine light came on tonight, well, let me start from the beginning. I got in and turned the key, no glow plug light, turned it off and tried again, still nothing. Then I started the car anyhow, hoping the light was burned out, and the check engine light came on, when it did, the display read "check engine electronics" and the glow plug light came on. Would this indicate that either the plugs are bad or the relay is bad? Ah, this is on the 96 E300D.

__________________
1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

If you pull the code it will prob be "PO380 GP/Heater circut malfunction". It will be generated if you start, or attempt to start, on cold GP's. If doesnt occur again within 3 cold/hot run cycles it will turn itself off.

Time to test your relay and check fuses as I doubt all 6 of your GP's went out at one time; but, you should check their resistance too to be certain.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

yeah it did it every time since it first started this morning. And my car doesnt have an engine block heater either.

__________________
1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

Where is the preglow time relay located? I would like to swap this part out myself. It looks to be a simple plug.

__________________
1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

I have the same year vehicle, and had the same issue with the glow plug light. In my case, it was an indication that one of my glow plugs had failed. Turned out to be the one right up against the firewall and oil filter housing. I replaced all six of the plugs, but I would not wish that job on my worst enemy. Only one plug came out without a problem. All the rest were carbon bound, and had to be nursed out by using PB Blaster, and a product called Freeze-Off. I used a torque wrench when applying pressure to loosen the plugs. According to information on this forum, the breaking point of the glow plug is around 45 n/m and the last thing you want to do is break off one of the plugs in the head. All in all, the job is not physically difficult, but it takes a lot of patience regarding letting the PB blaster do its job. Prior to installing the new plugs, I used a reamer obtained from ElPaso tools on ebay. It is manufactured by Baum tools and sells on ebay for about $55.00. Good luck with your vehicle.

would just one bad GP keep them all from working?

__________________
1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

hi again, In my case, the other 5 plugs were in fact working. When I started the car up cold, at around 30 degrees outside temperature, it would start with no problem, but I could hear that one cylinder was not firing like the rest. After a period of about 45 seconds to one minute after starting, the engine was running smoothly as usual. If you do a search, there are postings regarding how to test each plug via a multi-tester, and using the plug at the relay. In my case, after removing the intake manifold , I removed the plug connectors (which pull straight off), and tested each plug with my ohm meter. Five of the plugs gave me an ohm reading of about .06, and the one that was bad was at 0. With the intake manifold and resonance intake pipe removed, I was able to clean out the carbon inside each one. In my case, the resonance flaps were not moving freely due to carbon and sludge buildup which I corrected. Hope this helps....

It does help. None of mine are coming on, at least it doesnt sound like it. I am taking it tomorrow to get the plugs and the relay checked out.

__________________
1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"